sawyer



W. SAWYER. Apparatus for Treating Carbon Pencils for Electric Lights.

No. 224,612 Patented Feb. 17, 1880. F/6'./..

i N h A UNITED STATES PATENT OFFICE.

WILLIAM SAWYER, OF NEW YORK, N. Y.

APPARATUS FOR TREATING CARBON PENCILS FOR ELECTRIC LIGHTS.

SPECIFICATION forming part of Letters Patent No. 224,612, dated February17, 1880,

Application filed October 21, 1879.

To all whom 'it may concern Be it known that I, WTLLIAM SAWYER, of thecity, county, and State of New York, have invented certain new anduseful Improvements in Apparatus for Treating Carbon Pencils for Use inElectric Lighting, of which the following is a full, clear, and exactdescription.

When a pencil of carbon immersed in a hydrocarbon gas or liquid isheated to incandes' cence by the passage of an electric current, thesurrounding hydrocarbon is decomposed and a coating of pure carbon isdeposited upon the pencil. In hardness, density, and homogeneity thisdeposit is superior to ordinary carbon, and is especially valuable foruse in electric lamps operating upon the principle of incandescence.

In order to render the pencil of carbon incandescent its ends must beconnected with the poles of a generator of electricity, and inasmuch asthere is considerable expansion of the carbon under the heat to which itis subjected, it has heretofore been extremely difficult to obtainsmooth straight pencils.

The object of my invention is to obviate the difficulties that have beenexperienced, and 1 accomplish my purpose by putting the pencil undertension during treatment, whereby ex pansion is allowed for and thepencil drawn and kept straight.

Referring to the drawing accompanying and forming a part of thisspecification, A is a soap-stone or other insulating base, to which aresecured two parallel metallic rods, M N, which, at their upper ends, aresecured into an insulating cross-bar, 0. These rods are thus insulatedfrom each other, and, by means of the holes l l and set-screws k, theyare connected with the wires leading from the and poles of the generatorof electricity.

0 is a piece of metal hinged in the frame B, and carrying two carbonclamps, E E, which are held in place by screws 0 c. The verticalposition of the clamping apparatus is maintained or adjusted by means ofthumb-screw D, provided with shoulder b and pin a. This thumb-screw isinsulated in L by hard-rubber bushing j.

L is a tube secured to base A, having a slot,

h, running a portion of its length. In this tube slides arod, J, whichis secured in any position by means of set-screw 4. Upon the top of therod J, and fixed to it, is a flaring grooved piece, f, in which worksthe V-shaped cross-piece 0, attached to lever G. The two ends (I d ofthe forked portion G of lever G are also grooved, and in this grooveworks the V,-shaped cross-piece F, fixed to metal piece F. The cam H,pivoted in the forked piece I, fixed to rod J, serves to control themovements of the lever G, which is brought up against the cam H by theretractile force of spring g, adjustable by screw K, working in offset Lof tube L.

Attached to the piece F, and held in place by set-screws c c, are twocarbon clampingpieces, E E.

The operation of treating a pencil of carbon is as follows: Primarilythe forked end of lever G is depressed by throwing down the cam H. Thenone end of the pencil of carbon P to be treated is clamped between thecarbons E E. The piece F is then placed in position, as shown in thedrawing, and the lower end of the pencil is swung between the clampingcarbons E E, which are adjusted by thumbscrew D, so that the pencilhangs vertically. The lower end of the pencil is then clamped in E E.Next the cam H is thrown up, when the spring g, by its action to elevatethe clamp E E, puts a tension upon the pencil P, which draws and keepsit straight. Lastly, the whole apparatus is immersed in a bath of,preferably, olive-oil to a depth sufficient to cover the carbon clamps Eand the current of electricity applied. Traversin g the rod M, thecurrent passes, by means of a wire-comiection, to tube L and rod J, and,by way off 6 G d F and the clamps E E, to the pencil P and the clamps EE, and thence, by way of O B and the rod N, outward. The pencil isrendered incandescent, is increased in length by expansion aboutone-thirty-second of its original length, and, being drawn taut by theaction of spring g, emerges from the bath when the current is cut oft,preferably straight, and coated with a fine even deposit of the densestcarbon.

Having thus fully described my invention,

What I claim as such, and desire to secure by nection with the pencil 0rpencils to be treated, Letters Patent, is-- so constructed and arrangedas to put a ten- 10 1. In apparatus for electrically treating carsionupon the pencil 0r pencils during treatbonpencils;substantially asLlLSC1lb6(l,tll6COl11- ment.

5 bination of the end connections E E and E \VM. SAWYE l.

E, the lever G, and cam H. Vitnesses:

2. In apparatus for electrically treating ca-r- THOS. (JROUKER,

G120. W. SAWYER.

bon pencils, substantially as described, a con-

